Fuel injection system and manifold



July 11, 1961 J. DOLZA ETAL 2,991,776

3 Sheets-Sheet 1 I. 5 '{i v. I A

INVENTORS ATTOPMEY July 11, 1961 J. DOLZA ETAL FUEL INJECTION SYSTEM ANDMANIFOLD 5 Sheets-Sheet 2 Filed Sept. 15, 1958 [N VENTORS Jo/m 70/ July11, 1961 J. DOLZA ET AL 2,991,776

FUEL INJECTION SYSTEM AND MANIFOLD Filed Sept. 15, 1958 3 Sheets-Sheet 3g INVENTORS A T TO/PNEY United States Patent O 2,991,776 FUEL INJECTIONSYSTEM AND MANIFOLD John Dolza, Fent'on, and William H. Kolbe,Birmingham, Mich., assignors to General Motors Corporation, Detroit,Mich, a corporation of Delaware Filed Sept. 15, 1958, Ser. No. 761,102 7Claims. (Cl. 123-119) The present invention relates to an improvedcombination of a fuel injection system and manifold which coact in sucha way as to greatly decrease the underhood space formerly occupied bysuch elements. The problem of underhood clearance has become a veryserious one with the advent of the various accessory drive mechanismswhich are now appended to an engine coupled with increasingly severestyling demands for lower hood lines.

As a consequence, engine and fuel systems designers are caught in adimensional squeeze which has made necessary many engineering changes toaccommodate the space squeeze. The present invention is directed to sucha development as it pertains to the combinations and disposition of themanifold and fuel system in such a way that the cubic displacement ofsuch combination is considerably reduced.

The present invention relates specifically to a V-type engine utilizinga fuel injection system of the general type shown and described incopending application S.N. 591,889, Dolza, filed June 18, 1956, and nowPatent No. 2,957,464, issued October 25, 1960, and further which fuelinjection system combined with a ram tube type manifold as shown incopending application S.N. 608,935, Dolza, filed September 10, 1956, nowPatent No. 2,909,165, issued October 20, 1959.

In the present invention the ram tube type manifold is mounted upon theengine in the normal manner, however, the fuel metering system isdependingly supported from the manifold plenum chamber so as to at leastpartially extend within the V of the engine. The manifold and fuelmetering mechanism are then enshrouded or encased in such a way as toisolate the fuel metering system from the engine proper. At the sametime air is adapted to be supplied to the encased metering system froman intake preferably disposed at the forward part of the enginecompartment. In this way, the fuel metering system is maintained in arelatively cool condition during engine operation.

Other objects and advantages of the present invention would be apparentfrom a perusal of the detailed descrip tion which follows.

In the drawings:

FIGURES 1 and 2 are partially sectioned front elevational views of thefuel metering system as mounted on a V-type engine;

FIGURE 3 is a detail view along line 33 of FIGURE 2; and

FIGURE 4 is a side elevation of the manifold.

In the drawings, a V-type engine is shown generally at and includes acylinder block 12, cylinder heads 14 and 16, and rocker arm covers 18and 20. Rocker arm push rods 22 and 24 are adapted tobe operated off ofa camshaft, not shown, and which rods in turn are adapted, throughrocker arms, also not shown, to actuate inlet valves 26 and 28.

A manifold 30 is of the ram tube type as generally shown and describedin the aforenoted S.N. 608,935, Dolza application, now Patent No.2,909,165, and does not, per se, constitute a part of the presentinvention save insofar as it is uniquely combined with the fuel meteringmechanism indicated generally at 32. Manifold 30 includes a plenumchamber 34 from which a plurality of ram tubes or pipes 36 lead to therespective cylinder intake passages 38 and 40 in cylinder heads 14 and16.

2,991,776. Patented July 11, 1961 As best seen in FIGURES 1 and 3, thebottom wall' 42 of plenum chamber 34 is provided with a flanged opening44 upon which the fuel metering mechanism 32 is adapted to bedependingly supported.

Fuel metering mechanism 32 includes an air metering portion 46 and afuel metering portion 48. The air meter 46 includes an intake casing 50suitably connected to plenum chamber 34 through stud means 52. Athrottle valve 54 is fixed to a shaft 56 rotatably supported in intakecasing 50 and is adapted to be controlled by a suit-able lever 58 fixedto shaft 56.

As best seen in FIGURE 3, manifold air intake passages or ram pipes 36are divided into two axially spaced sets with the air meter 46 mountedtherebetween. The axial spacing is necessary to make room for the fuelmetering mechanism 32 and by intermediately disposing the latter bettercharge distribution is possible.

Air meter 46 also includes a tapered adapter member 60 mounted on thelower end of intake casing 50. Member '60 is axially spaced with respectto casing 50 by stud means 62 to provide a radially opening venturi airintake 64.

Air intake 64 communicates with an air chamber 66. Adapter member 60 hasan axial passage 68 formed therethrough which at its lower end likewiseradially communicates with chamber 66, the air fiow through which iscontrolled by a signal modifier valve 70. As set forth in detail incopending application S.N. 658,091, Dolza et -al., now Patent No.2,914,051 issued November 24, 1959, signal modifier 70 is adapted tomodify the vacuum signal transmitted to fuel metering mechanism 32 inaccordance with certain engine operating conditions such as temperature.

Thus, under low air flow conditions, or when the engine is cold, thesignal modifier valve will restrict the intake air flow to venturipassage 64 whereby a high air flow and consequently strong fuel meteringvacuum signal will be maintained as described in the aforementionedapplication.

Studs 62 are also adapted to support fuel metering device 32 in axiallyspaced relation to adapter member 60. Fuel metering device 32 issubstantially the same as that shown and described in Patent No.2,957,464 and therefore the same will only be described to the extentneces sary to an understanding of the present invention,

In the illustrated embodiment of the present invention, fuel meteringdevice 32 is adapted to supply fuel to a fuel distributor 72 inaccordance with the mass of air flow through venturi intake 64. Aplurality of fuel conduits 74 lead from fuel distributor 72 andcommunicate at their opposite ends with fuel nozzles 76 disposed inmanifold casing 30. Nozzles 76 project with intake passages 3'8 and 40and are adapted to project a stream of fuel against the backside ofinlet valves 26 and 28.

A casing member 78 is mounted between manifold casing 30 and cylinderheads 14 and 16 and is adapted to project within the V of engine 10, soas to enclose and isolate fuel metering mechanism 48 from the engine.

Manifold casing 30 is provided with side openings 80 and 81 forpermitting access to fuel metering mechanism 32 for servicing andadjusting purposes. The access openings 80 are adapted to be closed bycover plates 82 and 84. Furthermore, the ends of manifold 30 are closedby easing wall sections 86 and 88. Thus, manifold casing 30, casing 78,and plates 82 and 84, encase fuel metering mechanism 32 within airchamber 66.

Access opening cover 82 is provided with a suitable opening 90 thereinWith which a flexible air hose member 92 is adapted to cooperate tointroduce air into chamber 66. While not so shown, it is intended thatthe other or intake end of hose 92 will be disposed at the forward endof the engine compartment and will include suitable filter or aircleaner means to introduce relatively cool air into chamber 66. In thusproviding a shrouded fuel injection system, as described, andintroducing relatively cool air there into, a fuel metering system isprovided in which vapor lock presents no additional problemnotwithstanding the proximity of the system to the engine.

Nozzles 76 are of the atmospheric type as described in copendingapplication S.N. 512,175, Homfeld, filed May 31, 1955, now abandoned,and as such include air galleries 94 which are adapted to introducesubstantially atmospheric air into the nozzles at the point immediatelyanterior of where fuel is sprayed into intake passages 38 and 40. Ingeneral, it is the purpose of the atmospheric nozzles to insure that thequantity of the fuel metered is insensitive to variations in manifolddepression. 'However, as described in copending application S.N.662,928, Dermond, filed May 31, 1957, now Patent No. 2,860,616 issuedNovember 18, 1958, it is sometimes desirable to control the atmosphericair introduced into nozzles 76 for the purpose of providing fuelenrichment under cold starting and operating conditions. Accordingly,and as described in the Dermond application, a valve member 96 isadapted to be provided in a conduit 98 supplying atmospheric air to airgalleries 94. Valve 96 is temperature responsive such that under coldstarting or running conditions the quantity of flow through conduit 98is restricted until such time as the engine warms sufficiently. By thusrestricting the air flow through conduit 98 manifold vacuum acting onthe nozzles tends to increase the quantity of fuel fiow and henceprovide temporary fuel enrichment.

in the claims:

1. A charge forming device for an internal combustion engine of the Vtype which includes an air intake manifold, said manifold having aplenum chamber and a plurality of individual cylinder intake passagesleading from said plenum chamber to the respective cylinders of theengine, a fuel and air metering mechanism dependingly supported fromsaid plenum chamber and adapted to project within the V of said engine,casing means coacting with said manifold and said engine for completelyencasing the fuel and air metering mechanism, and means for supplyingair through said casing means to said mechanism.

2. A charge forming device for an internal combustion engine of the Vtype comprising an air manifold, said manifold having a plenum chamber,a plurality of intake passages communicating said plenum chamber withthe individual cylinders of the engine, an air meter dependinglysupported from said plenum chamber, throttle means in said air meter forcontrolling the quantity of air flow therethrough, a fuel meteringdevice supported from said air meter and projecting within the V of saidengine, first casing means cooperating with said manifold and saidengine to enclose said fuel metering device, second casing meanscooperating with said manifold to enclose said air meter, said manifoldand said first and second casing means defining an air chamber, andmeans for supplying air to said air chamber.

3. A charge forming device for an internal combus' tion engine 'of the Vtype comprising an air manifold. said manifold having a plenum chamber,a plurality of intake passages communicating said plenum chamber withthe individual cylinders of the engine, an air meter dependinglysupported from said plenum chamber, throttle means in said air meter forcontrolling the quantity of air fiow therethrough, a fuel meteringdevice supported from said air meter and projecting Within the V of saidengine, first and second casing means cooperating with said manifold andsaid engine to enclose said fuel metering device and said air meter,said manifold and said first and second casing means defining an airchamber, and means for supplying air to said air chamber.

4. A charge forming device as set forth in claim 3 in which theplurality of intake passages are divided into two sets of axially spacedpassages and further in which said air meter is disposed intermediatesaid sets.

5. A charge forming device as set forth in claim 1 in which saidmanifold includes a pair of walls enclosing the respective ends of saidmanifold and a pair of side walls each having an access opening therein,said casing means including cover plates adapted to coact with said sidewall openings.

6. A charge forming device as set forth in claim 5 in which said casingmeans includes a member mounted between the manifold and the engine forenclosing the bottom of the manifold.

7. A charge forming device as set forth in claim 5 in which said airsupplying means is mounted on one of said cover plates.

References Cited in the file of this patent UNITED STATES PATENTS2,843,099 Ransom et a1 Sept. 10, 1956 2,857,893 Lobdell June 10, 1957

